There have been a series of Evolution News posts responding to a critical review of Darwin’s Doubt, published in the journal Science. I have been keeping up with them, but when I read this post by Casey Luskin about a challenge from Charles Marshall against Meyer’s book, I really felt that I had to blog about it.
You have to read this to believe it:
In his review of Darwin’s Doubt in the journal Science, UC Berkeley paleontologist Charles Marshall claims that Stephen Meyer “completely omits mention of the Early Cambrian small shelly fossils,” which he claims causes Meyer “to exaggerate the apparent suddenness of the Cambrian explosion.” Yet both of Marshall’s claims are false. Meyer does not fail to mention the small shelly fossils and he does not exaggerate the brevity of the Cambrian explosion.
In the first place, Marshall has his facts wrong. Meyer does discuss the small shelly fossils on page 425 of Darwin’s Doubt. Meyer writes as follows:
The Cambrian period 543 mya is marked by the appearance of small shelly fossils consisting of tubes, cones, and possibly spines and scales of larger animals. These fossils, together with trace fossils, gradually become more abundant and diverse as one moves upward in the earliest Cambrian strata (the Manykaian Stage, 543-530 mya).
Nevertheless, although Meyer discusses the small shelly fossils, he does not treat them as a solution to the problem of the explosion of morphological novelty that arises later in in the Cambrian period. The small shelly fossils appear in the fossil record at the base of the Cambrian period about 542-543 million years ago. The main pulse of morphological innovation that Cambrian paleontologists commonly refer to as the “Cambrian explosion” first begins about 530 million years ago and then lasts about 10 years through the Tommotian and Adtabanian stages of the Cambrian period. During the first 5-6 million year stage (the Tommotian) of the explosion, between 14-16 novel phyla first appear in the fossil record. Without actually asserting that the small shelly fossils somehow explain the subsequent explosion of all these novel forms of animal life (or even that the small shelly fossils represent ancestors to all, or some, of these forms), Marshall faults Meyer for not treating them as part of the Cambrian explosion.
Now from this, you might expect that other biologists who do not believe in intelligent design think two things. One, that these fossils are important to explaining the Cambrian explosion. And two, that these fossils count as part of the Cambrian explosion – extending the period of innovation from 10 million years (at the most!) to 23 million years. In fact, you might expect that Marshall thinks that the small, shelly fossils DO explain the Cambrian explosion, and that the Cambrian explosion DID last 23 million years, and not 10 million.
But you’d be wrong – all of this nonsense about SSF is just a mendacious smokescreen to smear Meyer:
For example, in a 2006 paper in Annual Reviews of Earth and Planetary Sciences, Marshall acknowledges that these fossils are of unclear evolutionary affinities and importance. He calls them “largely problematic fossils” that are “hard to diagnose, even at the phylum level.” Figure 1 of his paper portrays them as apparently disconnected to the later radiation of Cambrian animals. This impression is reinforced in the text of his article where he notes that the small shelly fossils for the most part are “problematic” organisms of unknown classification…
Marshall himself does not think that the SSF are an explanation for the Cambrian explosion – he only insinuated that in his review in order to smear Meyer.
In fact, other naturalists agree with Meyer (and Marshall!) that these SSFs are not part of the explanation for the explosion in new information:
Other authorities agree that these small shelly fossils [SSFs] are of unclear evolutionary significance and affinity. In his book On the Origin of Phyla, James Valentine argues that the SSFs “are very difficult indeed to interpret.” Valentine’s 2013 book, The Cambrian Explosion, co-written with Douglas Erwin, notes that “many SSFs are still poorly understood.” Simon Conway Morris found them so unimportant that he does not mention them in either of his authoritative books on the Cambrian explosion (Crucible of Creation or Life’s Solution).
Valentine and Conway Morris are two of the top experts on the Cambrian explosion. Neither is a proponent of intelligent design.
But wait! There’s still more dishonesty from Marshall!
Marshall also argues that Meyer is mistating the length of the Cambrian explosion:
But what about the claim that Darwin’s Doubt exaggerated the brevity of the Cambrian explosion? Should Meyer have included the appearance of the early Cambrian small shelly fossils as part of the explosion when he estimated the length of that event? Not according to a very recent paper by Marshall himself. In 2010, Marshall co-wrote with James Valentine in the journal Evolution (emphases added):
By the beginning of the Cambrian Period, near 543 million years ago, a few kinds of “small shelly” fossils are found, <2mm in largest dimension. The small shellys rose to a peak in abundance and diversity during the period from 530 to 520 million years ago, when representatives of living phyla are found among them. During that same period, a chiefly larger-bodied invertebrate fauna of up to a dozen phyla, and including many soft-bodied forms, is also first represented by fossils. This geologically abrupt appearance of fossils representing quite disparate bodyplans of many living metazoan phyla is termed the Cambrian explosion…
Let’s unpack the construction of this paragraph, in which Marshall explains the length of the Cambrian explosion in relation to the small shelly fossils. Starting at the end of the quote, Marshall and Valentine equate “the Cambrian explosion” with the “geologically abrupt appearance of fossils representing quite disparate body plans.” They further identify this period with “that same period” wherein “a chiefly larger-bodied invertebrate fauna of up to a dozen phyla, and including many soft-bodied forms, is also first represented by fossils.” Marshall and Valentine also equate that period of time with “the period from 530 to 520 million years ago” and distinguish it from the earlier time in which the first small shelly fossils arose. Thus, according to Marshall — in a co-authored technical paper written in 2010 — the Cambrian explosion does not begin with the first appearance of the small shelly fossils 543 million years ago, or during the earliest part of the Cambrian period. Rather, he and fellow paleontologist James Valentine affirm that the explosion begins about 530 million years ago and lasted to about 520 million years — a date consistent with what Valentine has written elsewhere, including in his recent book with Erwin that Marshall cites approvingly in his review of Meyer.
Thus, by Marshall’s own admission, (a) the appearance of small shelly fossils around 543 million years ago does not mark the beginning of the Cambrian explosion, and (b) the Cambrian explosion should be dated to 530 to 520 million years when we see the “abrupt appearance” of many disparate body plans, long after the small shellies appear. This means that Marshall has acknowledged in print that the “Cambrian explosion” itself lasted only about 10 million years — just as Meyer affirmed in Darwin’s Doubt. Indeed, Marshall and Valentine affirm that SSFs appear long before the primary explosive radiation of Cambrian animals and they affirm a 10-million year duration for the Cambrian explosion.
So here you have a naturalist who is so desperate to smear a proponent of intelligent design that he has to resort to outright deception – deceptions which he knows are false from his own writings!
This reminds me of how Lawrence Krauss misrepresented that e-mail from Vilenkin during his debate with William Lane Craig. Apparently, naturalists just aren’t bound by the same sense of morality as theists. Should we be surprised that people who repudiate the idea of objective morality would then proceed to act dishonestly like this? In an accidental universe, anything goes – and truth is not as important as getting ahead in your career by any means necessary.
So the take away lesson for the rest of us is this: Sometimes you don’t need to understand all the scientific details exhaustively in order to know what to think about a controversial issue. You just have to spot the liar.
By the way, Dr. Meyer has some comments of his own about these small, shelly fossils in this post.